This application requests continued support for the tri-institutional Medical Scientist Training Program (MSTP) at Stony Brook University, Cold Spring Harbor Laboratory and Brookhaven National Laboratory. Continuously supported by the NIGMS since 1992, our MSTP has over a 30-year history of training physician-scientists, many of whom have gone on to make important discoveries and become leaders in biomedical research at academic medical centers across the country. Of our 87 graduates thus far, 30 are still in training, almost all in strong academic medical programs. Of the remaining graduates, 83% have academic faculty positions, many of which are highly prestigious, or are affiliated with university hospitals, NIH, or biotechnology / pharmaceutical groups. The goal of the program is to provide a rigorous training path that creates and fosters a physician-scientist mentality and a culture that imbues trainees with the tools, motivation, identity, and drive to pursue careers in academic medicine. Students are exposed to both clinical and basic scientific activities throughout their training, reinforcing the special nature of this program. Core courses unique to our MSTP include monthly seminar / dinners with both internal and external physician-scientist speakers, and a monthly journal club - clinical pathological correlation dinner-evening that combines basic science with clinical applications in an active-learning manner. Most recently, our students have been strongly encouraged to register for mini-courses in our new and internationally-unique Alan Alda Center for Communicating Science. PhD degrees are offered in a wide range of disciplines with the students being guided to undertake high-quality basic / translational science training to address problems relevant to human health. Since the last review, there have been many changes at SBU including (i) the recruitment of an extraordinarily dynamic physician-scientist Dean who in turn has recruited new MD and MD-PhD physician-scientists as Chairs of the major clinical departments and the Cancer Center, (ii) the founding of a new Biomedical Informatics department by an MSTP-trained physician-scientist, (iii) major new philanthropy, and (iv) the $423M construction in progress of a Cancer Center and Children's Hospital. The MSTP has grown from 40 students to 58, annual institutional support to the MSTP has risen by 60%, the applicant pool size has almost doubled, and both applicant and matriculant quality have increased substantially. In 2014/15, we are matriculating 7 students. Many of our students hold individual NRSAs, publish high-impact articles, and have received a variety of honors, both intra- and extramurally. Overall time-to-graduation has averaged 7.9 years over the past decade. Our program was recommended for 18 lines of support by the NIH study section and Council in the last review, but federal funding constraints resulted in the current level of support being held to 8 slots. In this application, we request the level of suppor approved in the prior cycle, i.e. 18 slots, in line with the recent growth of our institution. We ae committed to the training of exceptional physician-scientists, which renewed funding will greatly facilitate.